High-resolution panels used for high-end smartphones and the like are required to have a narrow frame to improve impression of the appearance. For example, a method of narrowing the width of a frame by placing a common driver circuit for a touch sensor and a gate driver circuit on both sides on the long sides of a panel in a high-resolution liquid crystal display device (LCD) having a built-in in-cell touch panel and using LTPS (Low Temperature Poly-Silicon) in a backplane has been studied (Patent Document 1).
However, further increase in the resolution of an LCD with a built-in in-cell touch panel increases the number of gate lines and accordingly increases the number of shift registers and buffers inside a gate driver, which causes a problem in that the operating frequency of the gate driver is increased. Furthermore, the layout area of the gate driver is increased, and it becomes difficult to achieve a narrow frame.